SYNOPSIS

DESCRIPTION

Listen
listens on a network for inbound calls to local services.
Proto
is the network protocol on which to listen, by default
tcp.
Incoming calls to any address
*
are accepted unless
addr
is specified with the
-a
option.
The services available are executable, non-empty files in
srvdir
or
trustsrvdir.
If neither
srvdir
nor
trustsrvdir
is given,
listen
looks for executable files in
/bin/service.
Services found in
srvdir
are executed as user
none;
services found in
trustsrvdir
are executed as the user who started
listen.
When changing user to
none,
a new namespace is created,
usually by executing
/lib/namespace,
but
-n
selects an alternate
namespace.
The
-p
option limits the number of processes that
listen
spawns to service the connections. If the
maxprocs
limit is reached,
listen
will log the event and delay servicing until the number
of connection processes drops below the limit again. A
maxprocs
smaller or equal zero means no limit (default).
Option
-q
suppresses affirmative log information.
Option
-i
suppresses the periodic scan of the service directories for changes.

Service names are made by concatenating the name of
the network with the name of the service or port.
For example,
an inbound call on the TCP network for port 565 executes service
tcp565.

At least the following services are available in
/bin/service.

tcp564

serve a piece of the name space using the Plan 9 file system protocol,
with authentication via
Tauth
(in
attach(5)),
no encryption,
and multiplex multiple users on a single connection
(used by
srv(4),
and also by Unix systems to see Plan 9 files).

tcp17007

serve a piece of the name space using the Plan 9 file system protocol,
with authentication at the start,
optional SSL encryption,
and no multiplexing of users
(typically used by
cpu(1)
and
import(4)).
Not usable by user
none.

tcp17008

like
tcp17007,
but serves the root of the tree,
forgoing the negotiation for which subtree to serve.

At least the following services are available in
/bin/service.auth,
the usual
trustsrvdir.

tcp566

validate a SecureNet box.

tcp567

Plan 9 authentication-ticket service.

Listen1
is a lightweight listener intended for personal use,
modeled from Inferno’s
listen(1).
announces on
address,
running
cmdargs...
for each incoming connection;
the network directory is passed in the environment
as
$net.
Option
-t
causes
listen1
to run as the invoking user; the default
is to become
none
before listening.
Option
-v
causes verbose logging on standard output.
See
/rc/bin/tlssrvtunnel
for an example.